I went through the upgrade from the latest previous version to EE6 using the automated button.
Everything came back green, except I'm now getting this error message:
Your system folder path does not appear to be set correctly. Please open the following file and correct this: index.php
My system folder is just "system" and both files appear to be set correctly. The only thing I can think of is that I had a soft-link to "backend", and when I did the upgrade, I was at "https://www.website.com/backend". I had never considered this an issue or possible item before.
(Renaming "system" to "backend" and updating the two php files does not resolve, unfortunately...)
Any help is greatly appreciated. :-D